Extraction Cell 3Decontamination Completed – December 30, 2009 - The floor of XC-3 has an area of over 300 square feet, and from its floor to its hatch into the Extraction Chemical Room (XCR) above it is 60 feet. XC-3 contained 14 principal vessels and 5800 linear feet of piping. The vessels had a total volume of about 1250 cubic feet and empty weight of almost 42,000 pounds. Vessels ranged up to 14 feet in length and 13,000 pounds in weight. Nine of 14 vessels were suspended at different levels within this “tower” cell, complicating their removal. At the beginning of this work, the cell’s vessels were estimated to contain about 2300 Curies. Decommissioning of the cell began in August 2008, following the successful acid flushing of some vessels, performed in order to reduce external dose to operators within the cell. Because of limited space on the floor of the cell, almost all cell entries were made from the XCR above via spider basket. Removal of piping and vessels was performed from the top down, with six levels of scaffolding demolished as the work descended to the floor of the cell. All debris was also removed through the hatch to the XCR, including the 14 vessels, each of which was lifted from the XCR to a shipping containing with a heavy lift crane brought to the site.

Liquid Waste Cell Decontamination & Decommissioning Preperations

Decontamination work continues in the LWC which contains an estimated 4400 linear feet of piping. The piping will be removed and the nine in-cell vessels are to be decontaminated and readied for removal during the next contract. Initial entries into the cell to perform surveys have indicated challenging external doses from contamination remaining in the empty tanks as well as exceptionally heavily contaminated floors.

Off Gas Cell
By the end of this contract, all piping and vessels are to be removed. In order to reduce employee dose, the floor will be grouted and a heavily contaminated north wall either scabbled or shielded before large scale manned entries. Approximately 200 Curies remain on the north cell wall. Initial manned entries will remove asbestos containing material from the tanks. The total volume of the eleven vessels in cell is about 1600 cubic feet with a weight of approximately 22,000 lbs.Head End Cells
By late spring or early summer, the Process Mechanical Cell should be decontaminated using Nitrocision. This technology involves blasting contamination from the lined walls of the cell using liquid nitrogen at about 55,000 psi pressure. The cell walls and floors are estimated to contain about 2500 Curies of contamination and it is anticipated that Nitrocision will be more than 90% effective.

Extraction Cell #1
This cell is the most contaminated in the building and will constitute the most difficult project because all in-cell work must be performed using remote tools due to the extremely high external dose emanating from some of the vessels. So far work completed in this subproject includes primarily the design of systems needed to perform the in-cell work, as well as some ex-cell work.

Asbestos Abatement/Cold and DarkThis project includes removal of all accessible Asbestos Containing Material (ACM) and removal of all equipment, piping, and conduit from the building’s aisles. Before any conduit and piping can removed, it must be electrically or mechanically isolated. After all ACM is removal, all piping and conduits in the aisles will be removed. Current efforts are focused on gutting the entire 144 foot level of the building. This includes all ACM, piping, and conduit in the Process Chemical Room, original Main Plant Control Room, and the Upper Extraction Aisles.

Extraction Cell 3 Decontamination Completed - December 30, 2009 The floor of XC-3 has an area of over 300 square feet, and from its floor to its hatch into the Extraction Chemical Room (XCR) above it is 60 feet. XC-3 contained 14 principal vessels and 5800 linear feet of piping. The vessels had a total volume of about 1250 cubic feet and empty weight of almost 42,000 pounds. Vessels ranged up to 14 feet in length and 13,000 pounds in weight. Nine of 14 vessels were suspended at different levels within this “tower” cell, complicating their removal. At the beginning of this work, the cell’s vessels were estimated to contain about 2300 Curies. Decommissioning of the cell began in August 2008, following the successful acid flushing of some vessels, performed in order to reduce external dose to operators within the cell. Because of limited space on the floor of the cell, almost all cell entries were made from the XCR above via spider basket. Removal of piping and vessels was performed from the top down, with six levels of scaffolding demolished as the work descended to the floor of the cell. All debris was also removed through the hatch to the XCR, including the 14 vessels, most of which were lifted from the XCR to a shipping containing with a heavy lift crane brought to the site.